I have so many "but if's" that I'm reluctant to post
I do eat for my type (with a few exceptions like cottage cheese).
I did not read all the hoopla ... I took my friends word for it and just tried the foodlists.
Even the author clearly states that if you eat too much of anything, you'll gain weight.
I gained weight when I started.
I'm fortunate that my type is basicly low fat, clean foods.
I disagree with the exercise suggestions.
I'm pretty sure that it is a coincidence that mine suits me very well. On the other hand, the ailments that he speaks of for my type if not cared for, are prevalent in my family. Another coincidence? Maybe.
So ... all in all ... it probably won't hurt you. Don't spend much on the books. And remember that it really is all about eating less and moving more.